Process and apparatus for deriving fiber from flax straw or the like



Sept. 20, 1938.

PROCESS AND APPARATUS FOR DERIVINGFIBER, FROM FLAX STRAW on THE LIKEOriginal Filed July 23, 1931 1 b mm um um H1 Q 2 m .H .w/x mm It I 2Sheets-Sheet 1 2 Sheets-Sheet 2 d flu w n .4 RN W 9w a A m m w m w w wwH Q Q\ 9w w N 2 0 o w o o W .k QQQ .WJ 7. o m o w o w mv owvw w a v N N%0 v R. FORSYTH Sept. 20,1938.

PROCESS AND APPARATUS FOR DERIVING FIBER FROM FLAX STRAW OR THE LIKEOriginal Filed July 23, l931 Patented Sept. 20,

PATENT OFFICE PROCESS AND APPARATUS FQR DERIVING FIBER FROM FLAX STRAWOR THE LIKE mum Forsyth, crammin assignor to Robert N. Burton, Chicago,Ill.

Application July 23, 1931, Serial No. 552,618 Renewed November I, 1936 1Claims. (01. 19-7) This invention relates to a process and to apparatusfor performing the process of separating or deriving from certainvegetable stalks or stems the fibrous structure thereof in the form 5 ofindividual fibers. Such fibrous material is adapted for use in thetextile art for spinning and weaving thread and cloth in the nature oflinen; it is also valuable for the manufacture of certain grades ofpaper commonly known as bond" paper and for the paper stock employed forcurrency; another and quite different use for such fiber is for packingor wicking for which it is suitable by reason of its capillary structureand in which capacity it may replace the cotton waste commonly employedfor packing journal bearings like those of railway car axles. These areonly afew examples of the range of uses of such fiber. The process isdesigned and illus trated with respect to the treatment of threshed flaxstraw, or like material, in such manner that the entire straw can bemade available for use by --separation into itscomponent parts includingthe Woody portion or shive, the gum and resin, the tannin and chlorofyland the fiber itself.

An object of the invention is to provide a process and apparatus formechanically accomplishing this purpose; another object is to insure arelatively gentle treatment of the fiber throughout 3 the process sothat it shall retain all of its original tensile strength and otherdesirable qualities without the impairment which might result fromexcessive chemical treatment or rough mechanical handling; anotherobject is to maintain the fibers as far as possible in their originalunbroken length and in substantial alignment through the process toavoid tangling and breakage; and it is also an object of the inventionto provide a substantially continuous process adapted to op- 40 elate ona definite time schedule whereby a given plant may be depended upon toturn out a known quantity of finished fiber in a given time with thevarious steps of the process under definite control at all times. Otherobjects will appear 5 as the description proceeds. The inventiontherefore consists inthe various steps of the process in combination andin certain features and elements of the apparatus and the relativearrangement of the parts thereof, all as hereinafter 50 described andshown in the drawings and as indicated by the claims.

Figure 1 is a diagrammatic side elevation of the apparatus for theinitial steps of the process including a feeding belt, flattening rollsand ad- 55 ditional rolls for flexing the straw and a picker of the dryfiber.

of typical construction, all for treating the straw in the dry state.

Figure 2 illustrates diagrammatically in vertical section the firstseries of troughs in which the fiber is treated for softening the gumsand 5 resins and also squeezing rolls associated with said troughs,together with a portion of the second series of troughs from which thematerial is fed from'the rolls.

Figure 3 is in'effect a continuation of Figure 2 10 showing the terminalportion of the second set of troughs with additional squeezing rolls andalso a neutralizing acid bath, a rinsing water bath, the final squeezingrolls, a traveling dryer belt and a set of rolls for mechanicalsoftening 15 Figure 4 is a diagrammatic detail mainly in section,showing the corrugations of the fiexing rolls illustrated in Figure l,and including. one of the hook shaped picker teeth to which said 20rolls feed the straw.

Figure 5 is a transverse section of one of the tanks or troughassembliesQbeing taken substantially as indicated at line, 5-'5, onFigure 2.

Figure 6 is adetail elevation of the squeezing 25 rolls shown in Figure2.

Figure '7 is a detail section on a larger scale showing the constructionof the troughs of Figure 5. t

Figure 8 is a partial plan view of said troughs. 30

This process having been designed primarily for the treatment of flaxstalks or straw and particularly for handling thrashed flax straw, willbe described with reference to that material although it may beunderstood that the process 5 may be suitable wholly or in part forderiving the fibrous content of other similar plant growths. It may beunderstoodthat the process is designed primarily to employ the strawshortly after the threshing process has been completed, 40

but preferably with the straw thoroughly dried.

Thatis, it isnot intended or contemplated that the straw shall be rettedas was once the practice, by permitting it to partially rot on the iground or under water to allow deterioration of the wood portion,

since such treatment has a tendency to deteriorate and weakenthe fiberitself as well as to waste the woody material or shive which itself hasa definite value, as for use in various wood pulp products, includingnews print.

Assuming then that the straw is supplied in a dry condition, it is fedby any convenient means such as by a conveyor belt, I, for deliverybetween a pair of plain rolls, 2, 2, which serve to flatten the strawand tend to split the fibers apart to some extent, and partially breakup the woody material adhering to them. For further loosening thismaterial, the, straw passes'directlybetween several pairs of flutedrolls whose grooves or corrugations are smoothly rounded and extendlongitudinally, that is, parallel to the axes of the rolls and withoutany sharp edges. Four pairs of such rolls are shown at 3, 4, 5 and 8 inFigure 1, and

from Figure 4 it may be noted that these rolls are ance space betweenthe first pair of rolls is greatseries.

' er than that between construction,

as a suggestion in dotted outline two the second pair, while the widthof the flutings and the clearance space between the flnal pair of rolls,6, 6, is the least in the The purpose of this arrangement is to causethe rolls to mildly fiex the straw as it passes through them, tending tobreak the woody portions into short-sections and to loosen them from thefibers themselves, ly more severe when vthe straw reaches. the final setof rolls, I, 8, than when it enters a set of rolls, 8, I. As a result ofthis treatment the fibrous stalks shed a considerable portion oitheirwoody content or "shive" before they reach. the drum, 1, of the picker,8, and are caught up by the hooklike teeth, I, 0! said drum to becarried through the picker. This machine may be similar to those usedfor a like purpose and of generally standard it being'u'nder'stood thatits function is to comb the fibrous material by means of toothedrolls-tendlne'to split the fibers apart and straighten themout and atthe same time serving to break oil most or the-remaining fragments andparticles of the woody material or shive. Merely for the pickerJ, I haveindicated pairs of so-called "working" rolls at II and I4, and a finallarge delivery roll or drum, II, by which it may be understood the fiberis discharged over a suitably inclined chute or table, it, into areceiving basket or car, It.

The dry fiber which isthus loosely piled or coiled in the receptacle,l3, may be-accumulated' as desired, as for example, until the receptacleis well filled, at which time the accumulated fiber will be definitelywhich continues another receiving car or basket being placed in positionand the first car being wheeled to the receiving end'of the tank, l4, atA. The cut or broken ends of the bunched or assembled to form a "silver"which may be started through the trough-like structure of the tank, I4,either by tying it with a string and leading the string through the feedrolls, ii, at the opposite end oi the tank, l4, or by leading thesliver" itself through the tank and'starting 7 its end portion throughthese rolls, l5. It is desirable, however, that the fiber shallexperience a soaking treatment in the heated water bath of the tank, l4,for a period of at least thirty-five minutes; therefore, if the leadstring is not employed, the sliver will be merely drawn through thelength of the tank, i4, and allowed to lie there for this period beforebeing started through the feed rolls, II. f

The tank, l4, as more clearly indicated in Figure 5 consists of outerside walls, I1, and a bottom wall, l8, within this treatment beingslight- -insure the treatment cut or brolren .ofi' from thatto dischargefrom the picker,

fiber in the receptacle, ll, are

said rolls aligned with the several troughs, It, and

which are shown longitudinally the side walls, I I, with communicationports or opening tom. Near the top of the tank and below the upper edgesof the side walls. II, a series of longitudinally extending troughs, 2|,aresupported on wardly between the sidewalls, l8, and their adiacentbailles, II, and thence horizontally over the troughs, 2|, anddownwardly through their perseveral so called "slivers" will be disposedin the or assemblies of fibers 7 respective troughs, 2!, as many asthree slivers to'each trough if dedred, and that as soon as these teredin the feed rolls, II,

F. and 212 F. by means ofthe livesteam in the pipes-24, andtheconvection currents set up in the-tank, l4,as describedwiliservetooft-heflberbysubstantialiy thewhole-mass of waterinthetankratherthanbyanylocalized softens the gum and reslnom material rendering itrelatively plastic. If the process is continuous the water in the tankor vat, i4, maybe changed tank, into a short open com t, 21, having,

'an outlet, II, which may lead into the sewer or to any suitablereceptacle if it is desired to recover the dissolved matter from thewater. A drain plug, 29, may also be provided near the bottom of thepartition wall, 20, for use in occasionally flushing out the entiretank, i4,'at which times any resinous matter which has settled in thetank may be collected and removed.

The fiber will not be injured by treatment with the hot water for alonger period than thirtyfive minutes. Therefore the initial portion ofthe fiber maybe allowed to lie in the troughs, 2|, this length of timeand then may be started through the feed rolls, ll. These rolls are heldtoward each other under adjustable spring pressure as indicated inFigure 2 and to accommodate the sliver. form in which the fiber is beinghandled, it may be preferable to provide one of with circumferentialgrooves, ll,

Droviding space for the thicker portions of the silver so thatsubstantially equal pressure may be exerted by each of the rolls uponall the fibers of each sliver. This pressure serves .to squeeze oil.fromthe fiber the major portion of the gum which hasbeen softened andloosened by the hot water treatment in the vat, l4, and this gummymaterial with the water which is also pressed out by the rolls, ii, isdischarged into a special accumulating trough, il and thence through anysuitable conduit, 2|, may be carll, inwardly from ing end of the silvera1so,ee1 'ried-off for reclamation in accordance with well understoodmethods. In the process of squeezing the hot-watersaturated sliverbetween the spring-pressed rolls, the rolls are exposed to the hot'waterby their contact with the silver.

Whatever length of silver it is possible to make from the initialquantity of fiber in the" receptacle, it, itwill be understood that thesilver may be rendered continuous by splicing onto it from time to timeadditional units of fiber as delivered from the picker, 8, and beforethe trailhas entered the trough of thetank, II. It should also beunderstood that in the structure as illustrated with multiple troughs,2|, started simultaneously and will continue to travel parallel to each,other through the appsratus. The fiber continues its movement throughthe rolls, l5, and enters the second set of troughs. 30, in a tank, 3|,structurally similar to the troughs, 2i, and their tank, It. The bath inthe tank, 3|, however, is a weak solution of sodium carbonate,preferably about'three percent, and for this reason the exposed metal ofthis structure should be of copper or heavily nickled to preventcorrosion and to prevent discoloration of the fiber which might occur ifordinary iron piping and tanks were used. The fiber travels through thetroughs. S0. at the same rate as it moved through the troughs, 2|. As amatter of convenience, if each set of troughs is made about thirty-fivefeet longthe fiber will be moved through them at the rate of one footper minute. And to avoid cooling and hardening of the gum during thetransfer of the fiber from the tank H to tank 3|, it may be subjected tohot water sprays at i5, and is adjacent the squeezing rolls, I5, asshown in Figure 2.

The function of the alkaline bath of sodium carbonate is to remove anyremaining gum from the fiber by dissolving it, thus freeing anyassociated resin from' the fiber and permitting it to fall to the bottomof the vat from which it may be collected at intervals for reclamationin mercharitable form. A small quantity of the alkaline solution may beadded from time to time to compensate for evaporation and for that whichis carried off with the gum and resin-removed in the vat, it. At the endof the tanlr, 36, the fiber again passes through squeezing rolls shownat M which remove most of the alkaline solution from it. These rolls maybe mounted directly in the end of the vat, ti, or, as shown, may beseparated from it and provided with a collecting trough, 33, for thesolution squeezed from the fiber. Asthe fiber approaches the rolls itmay be further clarified by a rinsing spray of clear water indicated atM.

For certain paper, it is desirable that even the small quantity ofalkali remaining in the fiber be neutralized, and for this purpose itmay be passed from the rolls, it, directly into a neutralizing bath ofwealr acid indicated at so. Brief dipping in this bath is all that isnecessary, therefore the tank, 35, may be of much less length than thepreceding tanks employed in the process and from it the fiber may bepassed through wringing rolls, 36, and then through a rinsing bath ofclear water, ii, to final squeezing rolls. it, which will press most ofthe moisture from the fiber. Emerging fromthe rolls, 38, it proceedsacross any suitable feed table or support, 3!, to a dryer which isindicated diagrammatically in Figure 3 as a a plurality of these sliverswill be these troughs and tanks being uses such as the manufacture ofcontinuous belt conveyor, ll, which may be understood as of any suitablereticulated form, as

for example, a series of belts or ribbons with transverse supportingbars secured to them at intervals. Associated with the dryer belt, 40,are suitable heating means such as steam pipes, ll, and a blower, 42,for supplying air through a distributing conduit, 43, with ports, 44,through which the air passes for heating contact with the pipes, GI, andthence through the conveyor belt, "I. for drying the fiber. 'At thedischarge end of the belt, 40, the fiber is preferably passed through aseries of fiuted rolls, l5, which may be similar to the rolls, 3, 4, i,S, employed at the beginning of the process except that they need nothave corrugations of graduated dimensions, as in the other series, butmay be all substantially alike; the function of these rolls, 4!, issimply to mildly fiex the fiber atthe completion of the drying to softenit and loosen from it any film of foreign material which may haveadhered through the various washings and rinsings; and may have beendried onto the surface in the final step of the process.

As it emerges from the softening rolls, 45, the fiber may be furthertreated by combing or card-' ing devices of any suitable design, as maybe readily understood by those skilled in the art.

spinning, it may be desirable to' subject the fiber to final chemicalbleach, but this can be extremely mild by reason of the fact that thematerial has already been so thoroughly cleansed and washed in theprocess herein described. As a result, the spinning fiber will be muchstronger than that which has been subjected to a relatively severebleaching, as such process always acts to weaken the cellular structureand therefore tends to weaken the strength of the fiber. Fiber producedin accordance with my process having been degummed almost entirely bymechanical means which at the same time is designed to handle the fiberalways gently throughout the process, will be found to present asoftness of texture and a. luster almost rivaling a silk fiber, andsince it has been thoroughly washed and cleared, it will take a fast dyerendering it suitable for spinning and manuiiacture into cloth for awide range of purposes for which linen has not heretofore been thoughtsuitable.

in theapparatus shown, as indicated in Figures 2 and b, I have includedvapor hoods, t l extending slightly above the side lls, ill, of thetanks and communicating with the suction passages, it", so as to draw cha and other vapors tending to rise from the surface of the liquids inthe tahknthus facilitating handling of the material if necessary byworkmen and keeping the premises clear of unpleasant steam and odors.Another feature of construction of the apparatus which is quiteimportant is the provision of oiled pressure pads of absorbent materialsuch as felt or the like shown at 90 in contact with u per and lowerrolls of each pair of squeezing rolls for the purpose of cleaning therolls of any adhering particles or fiber which would otherwise cling totheir associtact with the surfaces of hesion of the material and willalso act as scrapers to remove fiber which might otherwise be carriedaround the rolls.

Although I have shown and described herein a specific group ofmechanisms and apparatus for ing from the spirit and scope of theinvention.

I claim:

1. A process for the purpose indicated which includes forming thefibrous material into a sliver after the shive has been removedtherefrom and feeding it slowly through a heated water bath to softenthe gum and resin and dissolve out the water-soluble material, passingthe silver between rolls for removing the softened gum and resin andprotecting the sliver against atmospheric cooling by spraying it withhot water in its passage to and through the rolls.

2. A process for the purpose indicated which includes loosening theshive or woody material mm the fiber in its dry state and separating asubstantial portion of the said material therefrom, then submerging thefiber i'or soaking it in liquid maintained at a temperature suitablefor.

and directing a softening the gum and resin, liquid current maintainedat said temperature into impact with the sliver while the latter is freefrom mechanical pressure and without substantial time interval betweenthe submergenee of the fiber for soaking it and its exposure to theimpact of the liquid current; whereby the gum is main tained in saidsoftened condition throughout the step of separation by liquid currentimpact.

3. A process for the purpose indicated which includes forming thefibrous material into a sliver after the shive has been removedtherefrom, feeding the sliver slowly through" a bath of water maintainedat a temperature suitable for softening the gum, exposing the sliver tothe directimpact of a current of water maintained at said temperaturewithout substantial intermission in the exposure to liquid maintained'at said gumsoftening temperature and while exposed to said liquidcurrent impact, passing the sliver between squeezing rolls the surfacesof which make conthe sliver for squeezing, the surfaces of the rollsbeing thus exposed to said liquid.

4. A continuous process for the purpose indicated which consists infeeding dry stalks or straw through instrumentalities adapted to applypressure and limited fiexure thereto forloosening the shive or woodymaterial, and-then continuing the movement through a picker arranged forcombing out and removing most of said woody material, forming into asliver the fibrous portion of the straw emerging from the picker andfeeding said sliver longitudinally at a relatively slow rate through aliquid bath maintained at temperature suitable for softening the gum,then without intermission in the exposure of the silver to the liquidmaintained at said gum-softening temperature, passing the sliver betweensqueezing rolls in direct contact of the fiber with the surface of therolls on opposite sides of the sliver while maintaining the sliver inexposure to the liquid maintained at said gum-softening temperature,splicing additional fibrous material from the picker to the sliver atintervals toextend the length indefinitely, feeding the silver afterpassing the rolls into a mild chemical water bath through which it moveslongitudinally at the same rate of speed to permit the remaining gum tobe dissolved and the associated resinto be freed from the fiber, thenfeeding the fiber through additional pressure means, rinsing and dryingit, and finally subjecting said fiber to mechanical fiexure forsofteningit, and to combing or carding means for removing any adheringparticles and straightening the fiber. I 5. A process for the purposeindicated which includes forming the fibrous material into a sliverafter the shive has been removed therefrom and ,feeding it slowlythrough a heated water bath to soften the gum and resin and dissolveout, the

water soluble material, feeding the sliver out of said bath and thenpassing it between rolls for dislodglng the gum and resin while applyingheat to protect the sliver against atmospheric cooling during itspassage to and through the rolls.

6. A process for the purpose indicated which includes forming thefibrous material into a silver afterthe shive has been removed therefromand feeding it slowly through a heated water bath to soften the gum andresin and dissolve out the water soluble material, feeding the sliverout of said bath, then subjecting it to mechanical pressure to dislodgethe gum and resin and applying heat to the sliver immediately upon itsemergence from the heated water bath to prevent cooling and hardening ofthe gum before its dislodgement.

7. A process for the purpose indicated which includes forming thefibrous, material into a sliver after the shive has been removedtherefrom, subjecting the fiber to .a heated liquid bath to dis-' solveout the coloring matter and soften the gum and resin, then separatelydislodglng and collecting the softened gum and resin outside said liquidbath while applying heat to prevent cooling and hardening of the gum andresin.

ROBERT FURSYTH.

